Abstract: In order to study the distribution law and influence effect of the-0.5 mm fine coal on the air heave medium fluidized bed, a fine coal content distribution st andard difference, an ash content distribution standard difference of the fine coal and a pressure fluctuation standard difference within the stabilized sections were appli ed to analyze the fluidized quality and separation performances of-0.5 mm fine coal on the separation fluidized bed.The results showed that-0.5 mm fine coal would obv iously affect to the fluidized quality, small amount-0.5 mm fine coal could promote and form an uniform and stable density separation fluidized bed, more-0.5 mm fine Co al content would not favorable to the density stability of the fluidized bed and the optimal initial content of-0.5 mm fine coal would be 6% under the test condition.Meanw hile the distribution law of-0.5 mm fine coal on the fluidized bed was revealed to provide the basis to the separation stable control of the air heave medium fluidized be d.